APA (7th ed.) Citation

Allen, R. C., Smith, R. A., & Barrett, L. P. (1916). Geological map of Michigan. Geological Survey of Michigan.

Chicago Style (17th ed.) Citation

Allen, R. C., R. A. Smith, and L. P. Barrett. Geological Map of Michigan. [Lansing, Mich.?]: Geological Survey of Michigan, 1916.

MLA (9th ed.) Citation

Allen, R. C., et al. Geological Map of Michigan. Geological Survey of Michigan, 1916.